[Charles Martel]

Having ridden on subway vehicles in NY, Washington DC, London, Munich, Frankfurt, Berlin, Hamburg, etc....I can say that when you have seats that go along the window....all guys do it. When you have normal seating...guys typically don’t do it.

Having ridden many of those same subways, I agree. Part of the issue is, as noted above, the low seating height. The other factor in play is that the inboard-facing seats are usually at the ends of the subway cars, near the doors - where most of the ingress/egress traffic bunches up. I think most men are just trying to keep their feet and knees out of traffic, and they subconsciously "spread" while doing so.

[Vigilanteman]

I spent 14 years of my life working in two of Japan's larger cities (Tokyo and Kobe). The reality is that the width from butt cheek to butt cheek doesn't vary much whether your legs are spread or not.

One night, I was lucky enough to find a seat for my commute home. Three stops later, an elderly man and his wife get on at the opposite end of the car. I hear him tell her "Let's go over by that foreign guy, they are kind to ladies and yield their seats." What else could I do?

But I learned NOT to yield my seat to young ladies. I once did so and a stop or two later and elderly lady gets on and the young twit I gave my seat to just kept her head down and pretends not to notice.

Live and learn.